The Phylogenetic Influence of Yersinia Infection on Human Major Histocompatibility Complex (HLA)

Abstract

One of the principal thoughts of this book is that host-parasite relationships have evolved as the result of intimate mutual interactions between the host and microorganisms (Chap. 12, Summary of Part II). In this regard, the involvement of Y. pestis as the dreadful pathogen in the genetic alteration of the European population during the Middle Ages (Vogel et al. 1960) was noted in Chap. 1, Part III (p. 181). At the present time, however, it is difficult to trace the influence of Y.pestis on the human major histocompatibility complex (HLA). Instead, some chronic diseases that have been recognized as autoimmune diseases are suspected as being related to HLA, and Y. enterocolitica infection is also included among them from human statistical immunogenetic data using the term “relative risk” in relation to a particular HLA type. According to Svejgaard et al. (1980), a positive association exists between disease and the particular HLA type if the relative-risk index is above one, and if the index is below one, a negative association exists between them. Based on this definition of “relative risk”, the indirect association of Y. enterocolitica infection with a certain HLA type attracted attention, because Catteral (1976) reported a Reiter’s disease syndrome that particularly occurred after infection with Y. enterocolitica and the possession of HLA-D/DR3 has a relative risk of 3.7 to Reiter’s syndrome. However, Svejgaard et al. (1980) showed a relative risk of 37.0 of HLA-B27 type (Table III.27) to Reiter’s syndrome.